Metal paste and production process of metal film

ABSTRACT

According to the present invention, a metal paste comprising an organo- or inorganometallic compound of a metal that is a solid at ordinary temperature and belongs to group 3 through 15 of the periodic table, and an amino compound as medium, and which exhibits coatable viscosity, is provided. By using the metal paste, metal films of various types of metals or alloys can be formed inexpensively with an industrially simple process and apparatus even on various types of general-purpose, inexpensive substrates having a low softening point such as a glass, plastic, film and so forth, in addition to a ceramic substrate. In particular, the metal film can be formed easily in an ordinary pressure onto a printed wiring board or a substrate to be coated with a metal, which has a poor heat resistance.

TECHNICAL FIELD

The present invention relates to a metal paste and a production processof a metal film. More particularly, the present invention relates to ametal paste that is able to form a metal film by low-temperature baking,and a production process of a metal film that uses said paste. The metalpaste of the present invention is useful as the raw material of a metalfilm used for the surface treatment, coating, demagnetizing anddecoration of electronic materials, electronic devices and mechanicalmaterials, etc., and in catalysis and sterilization. Moreover, it isalso useful as the raw material of a metal film used in the fields ofpharmaceuticals and agricultural chemicals, etc.

In addition, if there was a process for easily producing a desired metalfilm even when metals are used directly as the base metal at present,there are many cases in which their use after forming into a metal filmwould be easier to handle and more economical. However, since baking athigh temperatures is required to form a metal film, the substrate islimited to materials having a high melting point. Therefore, if thebaking temperature for forming a metal film can be made lower,applications could be expanded to include general-purpose, inexpensivesubstrates having a low softening point (such as glass or plastic etc.).The present invention relates to a metal paste for low-temperaturebaking that allows this wide range of applications.

BACKGROUND ART

Metals have useful properties that are unique to each type of metal.Each of these types of metals are used either alone or in the form of analloy for surface treatment, coating, demagnetizing and decorating ofelectronic materials, electronic devices, mechanical materials and soforth, as well as catalysis, sterilization, and even in the fields ofpharmaceuticals and agricultural chemicals etc. by utilizing theirrespective characteristic performance (such as electrical conductivity,resistance, semi-conductivity, transparency, ionicity, corrosionresistivity, friction, light blocking, coloring and/or metallic luster)after forming into a film by various means on a substrate such asceramics and so forth.

The following lists examples of technologies of the prior art used toproduce metal films: (1) methods that require a high vacuum such assputtering; and, (2) methods in which metallic ink is applied and bakedsuch as the thick film paste method. The sputtering method of (1)requires an expensive, high-vacuum and large apparatus, has poormass-productivity due to batch production, and has high productioncosts. Consequently, the paste method of (2) is used because of its lowequipment cost and high productivity. In this method, various types ofmetal paste are coated onto a substrate and baked, allowing metal filmsto be produced continuously and inexpensively using a simple process andapparatus.

The paste used in this thick film paste method is a heterogeneousviscous liquid simply comprising forming various types of metal intofine particles and dispersing in a solvent. Coating and baking thisviscous liquid results in a metal film in which the metal particlessimply make contact, thereby preventing the formation of a uniform film.Consequently, in the case of silver-palladium alloy that is mostfrequently used in the electronics industry, even if formed with thethick film paste method, it is necessary to bake by heating to a hightemperature of about 950° C. and physically melt the metal particles toobtain a uniform thin film. Consequently, only ceramic substrates, metalsubstrates or other substrates having a high melting point could be usedfor the substrate on which the metal film is formed. In addition, alarge baking oven and peripheral facilities able to withstand hightemperatures, and an energy source and so forth for high-temperaturebaking are required to perform baking at high temperatures.

Consequently, if the paste baking temperature could be lowered further,equipment costs could be reduced, energy could be saved, and costs couldbe lowered. In addition, since it desirable to form a metal film on ageneral-purpose, inexpensive substrate having a low softening point(such as glass or plastic etc.), it is preferable to further lower thebaking temperature at which metal film is formed to allow use of thosesubstrates.

In order to overcome this shortcoming, a method has been proposed(organometallic (MO) method) in which inorganic metal particles arefirst converted to an organometallic compound, coated after uniformlydissolving in a solvent, and then baked to obtain a thin, uniform metalfilm. For example, in the case of gold, a paste method using anorganometallic compound containing sulfur allows the formation of auniform gold film demonstrating equal performance while requiringapproximately only {fraction (1/7)} the amount of gold as compared withthe thick film paste method in which fine particles of gold are kneadedinto a paste. Consequently, in fields that use gold, production isswitching over to the MO method from the conventional thick film pastemethod.

A synthesis method in which an organic substance is bonded directly to ametal to transform into an organometallic compound is typically used asa method for producing the above-mentioned organometallic compound. Inthis synthesis method, a special production method is required toconvert inorganic metal into an organometallic compound. In addition,since it is difficult to convert at a yield of 100% at that time, thismethod is more expensive than methods using metal and solvent. Thus,although this method can be used practically in the case the base metalitself is an expensive metal like gold, in the case of other metals, theuse of this method results in the cost required for the process ofconverting to an organometallic compound being higher than the price ofthe metal itself. Consequently, there is a need in industry for a metalpaste that allows metal films to be produced both inexpensively andeasily.

DISCLOSURE OF THE INVENTION

In consideration of the above-mentioned problems, the inventors of thepresent invention found that when a general-purpose, inexpensive solidorgano- or inorganometallic compound, and not a special, expensiveorganometallic compound, is mixed with a general-purpose, inexpensiveamino compound, it unexpectedly changes into a liquid or mud to allowthe obtaining of a coatable, viscous metal paste, thereby leading tocompletion of the present invention.

A production process in which an organo- or inorganometallic compoundcan be directly formed into a paste in the form of a metalloorganic (MO)ink by adding an amino compound to a solid organo- or inorganometalliccompound followed by a simple means of manipulation in the form ofstirring is not known in the literature.

According to the present invention, a metal paste is provided whichdemonstrates coatable viscosity and is composed of an organo- orinorganometallic compound of a metal that is a solid at normaltemperature and belongs to groups 3 through 15 of the periodic table,and an amino compound as medium.

Although organometallic compounds are typically unstable, the compoundis stabilized by the addition of organic acid and organic alcohol to theabove-mentioned metal paste, thereby providing a metal paste which ischaracterized by improving solubility and printability.

Moreover, according to the present invention, a production process of ametal film is provided characterized in that the above-mentioned metalpaste is coated onto a substrate and baked at a low temperature of 90°C.-550° C. to form a metal film.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) indicates an X-ray diffraction pattern, FIG. 1(b) indicatesthe peak data of FIG. 1(a), and FIG. 1(c) indicates the peak data ofsilver and palladium only.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, a metal compound belonging to group 3 through15 of the periodic table that is a solid at normal temperature includesthat presented in the form of a complex of a metal and carbonylcompound, an organometallic compound such as an organic acid metal salt,a metal cyanide and an inorganometallic compound such as nitric acidmetal salt.

Specific examples of a metal belonging to groups 3 through 15 of theperiodic table include palladium, platinum, rhodium, gold, silver,cobalt, lead, copper, indium, tin, antimony, ruthenium, cadmium,thallium, bismuth, chromium, manganese, iron, nickel, zinc, molybdenumand so forth.

Specific examples of nitric acid metal salts include palladium nitrate,rhodium nitrate, silver nitrate, cobalt nitrate, lead nitrate, coppernitrate, indium nitrate, tin nitrate, ruthenium nitrate, cadmiumnitrate, thallium nitrate, bismuth nitrate, chromium nitrate, manganesenitrate, iron nitrate, nickel nitrate, zinc nitrate and so forth.

Specific examples of metal cyanides include palladium cyanide, platinumcyanide, rhodium cyanide, gold cyanide, silver cyanide, cobalt cyanide,lead cyanide, copper cyanide, thallium cyanide, iron cyanide, nickelcyanide, zinc cyanide and so forth.

Carbonyl compounds include those which are able to form complexes withmetal, examples of which include complexes with acetylacetone,acetoacetic ester, acetopropionic ester and so forth. Specific examplesof complexes of metals and carbonyl compounds include complexes ofmetals and acetylacetone compounds such as acetylacetone platinum,acetylacetone rhodium, acetylacetone silver, acetylacetone cobalt,acetylacetone lead, acetylacetone copper, acetylacetone indium,acetylacetone cadmium, acetylacetone thallium, acetylacetone chromium,acetylacetone manganese, acetylacetone iron, acetylacetone nickel,acetylacetone zinc, acetylacetone molybdenum and so forth, complexes ofmetals and acetoacetic ester compounds such as ethyl acetoacetate zincand so forth, complexes of metals and acetopropionic ester compoundssuch as ethyl acetopropionate zinc, and complexes of metals and carbonylcompounds such as rhodium carbonyl and ruthenium carbonyl and so forth.

In addition, examples of organic acid metal salts include formic acidmetal salts, acetic acid metal salts, oxalic acid metal salts andcyclohexane propionic acid metal salts. Specific examples of organicacid metal salts include formic acid metal salts such as palladiumformate, indium formate, tin formate, antimony formate, silver formate,ruthenium formate and so forth, acetic acid metal salts such aspalladium acetate, rhodium acetate, silver acetate, cobalt acetate, leadacetate, copper acetate, indium acetate, tin acetate, antimony acetate,ruthenium acetate, cadmium acetate, thallium acetate, bismuth acetate,chromium acetate, manganese acetate, iron acetate, nickel acetate, zincacetate, molybdenum acetate and so forth, oxalic acid metal salts suchas palladium oxalate, rhodium oxalate, silver oxalate, cobalt oxalate,lead oxalate, copper oxalate, indium oxalate, tin oxalate, antimonyoxalate, ruthenium oxalate, cadmium oxalate, thallium oxalate, bismuthoxalate, chromium oxalate, manganese oxalate, iron oxalate, nickeloxalate, zinc oxalate, molybdenum oxalate and so forth, rutheniumcyclohexane propionate, palladium benzoate, silver benzoate and soforth.

The above-mentioned organo- or inorganometallic compound may be only onetype or a combination of a plurality of types. In addition, theabove-mentioned organo- or inorganometallic compounds may be in the formof hydrates.

Moreover, as the organo- or inorganometallic compounds, rhodiumacetylacetonate, gold cyanide, palladium acetate, thallium acetate,silver acetate, bismuth acetate, tin acetate, cobalt acetate, indiumacetate, copper acetate, antimony acetate, silver formate, palladiumformate, indium formate, tin formate, copper formate, rutheniumcyclohexane propionate and tin oxalate are preferable.

Amino compounds that can be used in the present invention include thosewhich allow organo- or inorganometallic compounds to be formed into apaste exhibiting coatable viscosity. Although liquid amino compounds areordinarily used in the present invention, solids may also be usedprovided they can ultimately be formed into a paste. More specifically,the amino acid compounds of the present invention refer to compoundsthat form coordinate bonds with organo- or inorganometallic compounds,and the products of which exhibit the properties of a paste. As a resultof their reaction, the organo- or inorganometallic compound exhibits acompatible state with the amino compound, and this is believed to resultin the formation of a paste with suitable viscosity. Thus, aminocompounds can be used even if they are a solid at ordinary temperature.

Preferable amino compounds are selected from the group represented withthe following general formulas [A] and [B]:

R¹—NH—(Z—NH—R²)_(n)[A]

R³—NH—Y—O—R⁴[B]

(wherein, R¹, R², R³ and R⁴ are hydrogen atoms, linear hydrocarbonshaving 1-8 carbon atoms or cyclic hydrocarbons having 3-8 carbon atoms(which may be substituted with lower alkylene groups), Z and Y arelinear hydrocarbons having 1-12 carbon atoms or cyclic hydrocarbonshaving 3-12 carbon atoms (which may be substituted with lower alkylenegroups), and n is 0-4).

More specifically, examples of compounds represented with generalformula [A] include diamino compounds such as 1,3-diaminopropane,N-methyl-1,3-diaminopropane,2,2-dimethyl-1,3-diaminopropane,1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane,1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane,1,7-diaminoheptane, 1,12-diaminododecane, 2-methyl-1,5-diaminopentane,1,2-phenylenediamine and 1,3-phenylenediamine, 1,4-phenylenediamine andso forth, and monoamino compounds such as N-methylaniline and1-phenylethylamine. Examples of compounds represented with generalformula [B] include monoamino compounds such as 2-methoxyethylamine,3-methoxypropylamine, 2-ethoxyethylamine, 3-ethoxypropylamine,3-propoxypropylamine, 2-amino-1-propanol, 2-amino-2-methyl-1-propanol,1-amino-2-propanol and so forth. Moreover, morpholine and so forth canalso be used in addition to these amino compounds.

The above-mentioned amino compounds may be used alone or in combinationof a plurality of types.

Here, monoamino compounds typically are inferior to diamino compounds interms of the stability of the metal paste formed. However, even in thecase of monoamino compounds, the following compounds:

NH₂—(CH₂)_(n)—OH;

or

NH₂—(CH₂)_(n)—OR

(wherein, R is a linear hydrocarbon having 1-8 carbon atoms or a cyclichydrocarbon having 3-8 carbon atoms (which may be substituted with loweralkylene groups), and n is 1-12) and their derivatives are not inferiorto diamino compounds, have various organo- or inorganometallic compoundsdissolved highly, and have been found to have extremely good stability.

For example, when gold cyanide is dissolved in ethylenediamine to form agold paste and then stored at room temperature, it decomposes in about 1day. However, when an amine larger than 1,3-diaminopropane is used underthe same conditions, the paste can be stored for a period from severalweeks to several months. It was found there is a difference in stabilitydue to their structures between compounds in which n=2 and n=3 or more.In other words, the stability of the metal paste was determined todiffer greatly according to the type of metal and type of amine.Moreover, since amines in which n is 3 or more in the diamino compoundNH₂—(CH₂)_(n)—NH₂ have excellent solubility and remarkable stability,and are able to provide a metal paste that can be baked at lowtemperatures, they are preferable.

The metal paste of the present invention is composed of a mixture of theabove-mentioned organo- or inorganometallic compounds and aminocompounds, and said mixture has a coatable viscosity. The presentinvention can be adjusted to the desired viscosity by changing the mixedamounts of the organo- or inorganometallic compound and amino compound.Here, it is preferable that the amino compound be contained at 0.2 molesor more, preferably at 0.6-17.51 moles, and particularly preferable at1.0-3 moles relative to 1 mole of organo- or inorganometallic compound.Furthermore, if the amount of amino compound is less than 0.2 moles, ittypically becomes difficult to obtain a viscosity that allows coating,which in addition to causing poor printability, makes it difficult todissolve the organo- or inorganometallic compound, thereby making thisundesirable.

If the molecular weight of the organic group contained in the metalpaste becomes large, a high temperature is required to form the metalfilm by baking. Thus, in order to lower the baking temperature, theorganic group should have a low molecular weight. However, if themolecular weight is excessively low, fluidity decreases which typicallyresults in poor printability and a poor formed film. Therefore, whenorganic acid and/or alcohol and so forth are added to the metal pasteand made an addition to a metal, printability and film formability canbe improved while holding down the baking temperature.

In particular, organic acids that can be added to the metal paste of thepresent invention are able to improve the stability and solubility ofthe metal paste by their addition even in the case of unstable organo-or inorganometallic compounds, change the baking temperature anddecomposition temperature, and improve film formability by making thebaked film homogeneous. In addition, by changing the type of organicacid according to the respective purpose or application, the bakingtemperature can be adjusted to form metal films having variousperformance.

Here, it is preferable to use an aliphatic or aromatic mono- ordicarboxylic acid represented with the following general formula [C]:

R⁵—(CooR⁶)_(n)  [C]

(wherein, R⁵ and R⁶ are hydrogen atoms, linear hydrocarbons having 1-20carbon atoms or cyclic hydrocarbons having 3-20 carbon atoms, both ofwhich may be substituted with alkylene groups, and n is 1-3 (providedthat n is 1 when R⁵ is a hydrogen atom)). In addition, the aliphatic oraromatic mono- or dicarboxylic acid may be substituted with substituentssuch as a lower alkyl group and so forth. Specific examples of aliphaticor aromatic mono- or dicarboxylic acids include formic acid, oxalicacid, acetic acid, propionic acid, butylic acid, valeric acid, caproicacid, heptanoic acid, caprylic acid, 2-ethylhexanoic acid, cyclohexanoicacid, cyclohexanepropionic acid, cyclohexaneacetic acid, nonanoic acid,malic acid, glutamic acid, leucic acid, hydroxypivalinic acid, pivalinicacid, glutaric acid, adipic acid, cyclohexanedicarbonic acid, pimelicacid, cork acid, ethylbutylic acid, benzoic acid, phenylacetic acid,phenylpropionic acid, hydroxybenzoic acid and so forth.

Although varying according to the particular type used, the additionratio of aliphatic or aromatic mono- or dicarboxylic acid is preferably0-5 moles to 1 mole of organo- or inorganometallic compound.

On the other hand, the addition of aliphatic or aromatic mono- orpolyhydric alcohol is able to improve the stability, solubility andprintability of metal paste even in the case of unstable organo- orinorganometallic compounds.

Here, it is preferable to use an aliphatic or aromatic mono- orpolyhydric alcohol represented with the following general formula [D]:

R⁶—(OH)_(n)  [D]

(wherein, R⁶ is a linear hydrocarbon having 1-20 carbon atoms or acyclic hydrocarbon having 3-20 carbon atoms, both of which may besubstituted with an alkylene group, and n is 1-4). Moreover, thealiphatic or aromatic mono- or polyhydric alcohol may have asubstituent, and it is preferable to use an aliphatic or aromatic mono-or polyhydric alcohol substituted with a cyano group represented withthe following general formula [E]:

(NC)_(m)—R⁷—(OH)_(n)  [E]

(wherein, R⁷ is a linear hydrocarbon having 1-7 carbon atoms or a cyclichydrocarbon having 3-8 carbon atoms, n is 1-3 and m is 1 or 2 (providedthat n+m=1-4 when R⁷ has 1 carbon atom, and n+m=1-6 when R⁷ has 2 ormore carbon atoms)).

Examples of aliphatic or aromatic mono- or polyhydric alcoholscorresponding to general formula [D] include nerol, citronellol,hydroxynerol, hydroxycitronellol, ethyl alcohol, propyl alcohol, butylalcohol, hexyl alcohol, ethylhexyl alcohol, decyl alcohol, benzylalcohol, hydroxybenzyl alcohol, phenylethyl alcohol, phenylpropylalcohol, dihydroxybenzene, cyclohexyl alcohol, ethylcyclohexyl alcohol,butylcyclohexyl alcohol, methoxybenzyl alcohol, piperonyl alcohol,ethylene glycol, propylene glycol,1,2-butanediol,2,2-dimethyl-1,3-propanediol and so forth.

Moreover, esters of the aliphatic or aromatic mono- or polyhydricalcohols represented with general formula [D] and organic acids can alsobe used. Specific examples of these compounds include methyl benzoate,ethyl hydroxybenzoate, ethyl 2-ethylhexanoate, ethyl acetate, ethylhydroxyacetate, methyl linolate and so forth.

Moreover, ether compounds of the aliphatic or aromatic mono- orpolyhydric alcohols represented with general formula [D] can also beused. Specific examples of these compounds include ethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, triethylene glycolmonopropyl ether, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, tripropylene glycol monopropyl ether, diethyleneglycol, dipropylene glycol, ethylene glycol monobutyl ether,1-butoxy-2-propanol and so forth.

Examples of aliphatic or aromatic mono- or polyhydric alcoholsrepresented with general formula [E] include lactonitrile,hydroxyacetonitrile, ethylene cyanohydrin, acetone cyanohydrin and soforth.

It is particularly preferable to add one of the above- mentionedaliphatic or aromatic mono- or polyhydric alcohols having the cyanogroup of general formula [E]. The addition of this alcohol makes itpossible to make unstable organo- or inorganometallic compoundsextremely stable and maintain a stable, transparent paste state. Here,although it is difficult to maintain a paste using a monovalent goldcompound in a stable state, addition of an alcohol having theabove-mentioned cyano group of general formula [E] enables this compoundto be stored at room temperature for roughly 4 years or more.

Although varying according to the type of alcohol added, the additionratio of aliphatic or aromatic mono- or polyhydric alcohol is preferably0-5 moles to 1 mole of organo- or inorganometallic compound.

Furthermore, both an aliphatic or aromatic mono- or dicarboxylic acidand aliphatic or aromatic mono- or polyhydric alcohol may be added to ametal paste.

Here, the printability of organometallic compounds is known to generallynot be good in the case of coating by printing methods. In the presentinvention, however, it was found that the addition of organic ketone ororganic ether to the above-mentioned metal paste changes it to a smoothpaste rich in spreadability. As a result, printability can be improved.Since storage stability is also improved, it is possible to form a thinand uniform metal film.

Aliphatic or aromatic ketones can be used for the above-mentionedorganic ketone. Specific examples of organic ketones include aliphaticketones such as acetone, ethyl methyl ketone, 2-pentanone, 3-pentanone,3-methyl-2-butanone, 2-hexanone, 3-hexanone, methyl butyl ketone,3-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, amyl methylketone, ethyl butyl ketone, 2,4-dimethyl-3-pentanone, 2-octanone,3-octanone, 4-octanone, 2,5-dimethyl-3-hexanone, cyclohexanone,methylcyclohexanone, acetylacetone, 2,3-butanedione, 2,3-pentanedione,3,4-hexanedione, 2,5-hexanedione, cyclohexanedione and so forth, andaromatic ketones such as acetophenone.

Aliphatic or aromatic ethers can be used for the above-mentioned organicether. Specific examples of organic ethers include aliphatic ethers suchas 4-methoxy-2-butanone, 4-ethoxy-2-butanone, 4-methoxy-2-butanone,2methoxy-2-methyl-4-pentanone, ethylene glycol dimethyl ether, ethyleneglycol diethyl ether, ethylene glycol dipropyl ether, propylene glycoldimethyl ether, propylene glycol diethyl ether, diethylene glycoldimethyl ether, diethylene glycol diethyl ether, dipropylene glycoldimethyl ether, dipropylene glycol diethyl ether, propylene glycolpropyl ether, acetal, acetone diethylacetal,2,2dimethoxypropane and soforth, and aromatic ethers such as anisol, dimethoxybenzene and soforth.

Although varying according to the type of compound, the addition ratioof aliphatic or aromatic ketone or ether is preferably 0-4 moles per 1moles of organo- or inorganometallic compounds.

Furthermore, aliphatic or aromatic ketone or ether may be added incombination to a metal paste.

The reason for obtaining a stable metal paste in the present inventionis believed to be due to the following action. Namely, when an aminocompound is added to a solid organo- or inorganometallic compound atordinary temperature and stirred, the organo- or inorganometalliccompound coordinates with the amino compound that has become a liquidresulting in the formation of a paste.

Furthermore, although there are cases in which crystallization occurs asa result of mixing depending on the particular combination of organo- orinorganometallic compound and amino compound, a paste can be formed atthat time if different types of amino compounds are used. In addition,although there are many cases in which the amino compound of an organo-or inorganometallic compound alone is unstable, since the addition oforganic acid results in the composition of a structure in whichpositivity and negativity are interlaced throughout the composition,active metal entrapped within are thought to be stabilized.

According to the production process of a metal film of the presentinvention, a metal film can be produced by coating a metal paste onto adesired substrate and baking. During the baking at this time, alcoholshaving weak bonding strength at low temperatures are separated afterwhich acids come off followed by amine coordination breaks down. As thetemperature rises further, organic groups directly bonded to metal aresevered resulting in the formation of a metal film. Since smallerorganic groups decompose more at lower temperatures than larger organicgroups at this time, a metal film is believed to be able to be producedat low temperatures. This is the mechanism of action responsible forforming a metal film as a result of making a solid organo- orinorganometallic compound form a paste and then making it decompose atordinary temperature.

Furthermore, metals are already used in various fields as an importantmaterial. Namely, the above-mentioned metals are considered to beimportant materials in the fields of electronic materials, mechanicalmaterials, optical materials, sanitary materials, domestic materials,agricultural materials, pharmaceutical materials and so forth. The pasteof the present invention can be used as an electrically conductivematerial, resistor material, heat transmitting material, heat insulatingmaterial, light and electromagnetic wave reflecting and absorbingmaterials, corrosion resistant material, mechanically strong material,material for absorbing abrasion, material for cataryst, metal lustermaterial, material for coloring, material for decoration or microbialgrowth-inhibiting material and so forth for which metals haveconventionally been used by utilizing the various propertiescharacteristic to metals in these fields.

The baking temperature is 90-550° C., and preferably 110-350° C. Thistemperature allows the heat treatment temperature to be loweredremarkably in comparison with methods of the prior art in whichtreatment is conventionally performed by heating to a temperature at orabove the melting point of the metal. Consequently, the process ofproducing a metal film of the present invention can also be applied to asubstrate on which a metal paste can be coated such as not onlysubstrates having a high melting point that are able to withstandheating at high temperatures (such as ceramics and metal), but alsoother substrates such as general-purpose glass, resins (thermosettingresins and thermoplastic resins), paper and so forth. Accordingly, itbecomes possible to provide a metal film coated substrate havingproperties characteristic to metals. Furthermore, low melting pointsubstrates in the form of a film or sheet are also included in thesubstrates in the present invention.

EXAMPLES

The following provides a detailed explanation of examples of the presentinvention.

Example 1

When 0.70 g (9.45 mmol) of 1,3-diaminopropane (NH₂CH₂CH₂CH₂NH₂), 0.70 g(7.94 mmol) of N-methyl-1,3-diaminopropane (CH₃NHCH₂CH₂CH₂NH₂) and 0.40g (4.49 mmol) of 3-methoxypropylamine (CH₃OCH₂CH₂CH₂NH₂) were added to1.00 g (4.34 mmol) of palladium nitrate (Pd(NO₃)₂) and stirred, a pastewas formed. When 1.20 g (13.62 mmol) of isobutyric acid ((CH₃)₂CHCOOH)were added and kneaded, a dark brown, nearly transparent paste wasformed. When this was coated on a substrate such as glass and so forth,heated to 320° C. and baked for 5 minutes, a palladium thin film wasobtained. Furthermore, in this example, 5.04 moles of amino compoundswere used to 1 mole of metal.

Example 2

When 0.60 g (8.10 mmol) of 1,3-diaminopropane, 0.20 g (2.27 mmol) ofN-methyl-1,3-diaminopropane, 1.50 g (19.97 mmol) of 2-methoxyethylamine(CH₃OCH₂CH₂NH₂), and 0.40 g (5.63 mmol) of lactonitrile (CH₃CH(OH)CN)were added to 1.00 g (6.31 mmol) of palladium cyanide (Pd(CN₂) andstirred, a transparent paste was formed. When this was coated onto asubstrate such as glass and so forth, heated to 300° C. and baked for 10minutes, a homogeneous palladium thin film was obtained. Furthermore, inthis example, 4.81 moles of amino compounds were used to 1 mole ofmetal.

Example 3

When 0.60 g (6.80 mmol) of N-methyl-1,3-diaminopropane and 0.40 g (5.33mmol) of 2-methoxyethylamine were added to 1.00 g (4.45 mmol) ofpalladium acetate (Pd(OOCCH₃)₂) and stirred, a transparent paste wasformed. When this was coated onto a substrate such as glass and soforth, heated to 250° C. and baked for 10 minutes, a homogeneouspalladium film was obtained. Furthermore, in this example, 2.73 moles ofamino compounds were used to 1 mole of metal.

Example 4

When 0.60 g (5.60 mmol) of N-methylaniline (C₆H₅NHCH₃) and 0.30 g (3.41mmol) of isobutylic acid were added to 1.00 g (4.45 mmol) of palladiumacetate and dissolved, a brown transparent paste was formed. Whenphenylethyl alcohol was added and kneaded as necessary, a darkreddish-brown paste was formed having improved printability. When thiswas coated onto a substrate such as glass and so forth, heated to 250°C. and baked for 10 minutes, a specular palladium film was obtained.Furthermore, in this example, 1.26 moles of amino compounds were used to1 mole of metal.

Example 5

When 0.20 g (1.05 mmol) of N,N-diethyl-triamide and 3.00 g (17.2 mmol)of hydroxycitronellol were added to 1.00 g (4.45 mmol) of palladiumacetate (Pd(OOCCH₃)₂) and stirred, a translucent paste was formed. Whenthis was coated onto a substrate such as glass and so forth, heated to250° C. and baked for 10 minutes, a homogeneous palladium film wasobtained. Furthermore, in this example, 0.24 moles of amino compoundwere used to 1 mole of metal.

Example 6

When 0.20 g (2.32 mmol) of methacrylic acid and 0.35 g (4.66 mmol) of2-methoxyethylamine were added to 1.00 g (4.45 mmol) of palladiumacetate and stirred, dark colored paste was formed. When this was coatedonto a substrate such as glass and so forth, heated to 230° C. and bakedfor 10 minutes, a homogeneous palladium film was obtained. Furthermore,in this example, 1.05 moles of amino compound were used to 1 mole ofmetal.

Example 7

When 0.40 g (3.73 mmol) of 1-phenylethylamine (C₆H₅CH(CH₃)NH₂) and 0.40g (3.92 mmol) of valeric acid were added to 1.00 g (4.45 mmol) ofpalladium acetate and stirred, this was kneaded until a dark brown pasteformed. When this was coated onto a substrate such as glass and soforth, heated to 250° C. and baked for 10 minutes, a homogeneouspalladium film was obtained. Furthermore, in this example, 0.84 moles ofamino compound were used to 1 mole of metal.

Example 8

When 1.00 g (8.76 mmol) of 1,2-diaminocyclohexane (C₆H₁₀(NH₂)₂) wasadded to 1.00 g (3.02 mmol) of platinum nitrate diaminopropanecoordination compound (NH₂CH₂CH₂CH₂NH₂ Pt(NO₃)₂) and kneaded, a lightbrown paste was formed. When a nearly equal amount of acetic acid wasadded and kneaded, a nearly transparent, light brown paste was formed.When both were coated onto a substrate such as glass and so forth,respectively, heated to 350° C. and baked for 5 minutes, platinum filmswere obtained. When a higher acid such as heptanoic acid and so forth isused at this time, adhesion was improved. Furthermore, in this example,3.90 moles of amino compound were used to 1 mole of metal.

Example 9

0.60 g (5.25 mmol) of 1,2-diaminocyclohexane and 0.30 g (4.05 mmol) of1,3-diaminopropane were added to 1.00 g (3.75 mmol) of thallous nitrate(TlNO₃) and stirred. A colorless, transparent paste was formed. Whenthis was coated onto a substrate such as glass and so forth, heated to170-180° C. and baked in a reducing atmosphere, a thallium film wasobtained. Furthermore, in this example, 2.48 moles of amino compoundswere used to 1 mole of metal.

Example 10

0.80 g (9.07 mmol) of N-methyl-1,3-diaminopropane were added to 1.00 g(2.50 mmol) of rhodium acetylacetonate (Rh(CH₃COCHCOCH₃)₃) to form apaste. When 0.60 g (6.81 mmol) of isobutylic acid were added andkneaded, a dark brown, transparent and homogeneous paste was formed.When this was coated onto a substrate such as glass and so forth, heatedto 390° C. and baked for 5 minutes, a rhodium film was obtained.Furthermore, in this example, 3.63 moles of amino compound were used to1 mole of metal.

Example 11

When 0.60 g (8.10 mmol) of 1,3-diaminopropane and 0.40 g (5.33 mmol) of2-amino-1-propanol (NH₂CH(CH₃)CH₂OH) were added to 1.00 g (5.63 meq) ofhexarhodium hexadecacarbonyl (Rh₆(CO)₁₆) and kneaded, a homogeneouspaste was formed. When this was coated onto a substrate such as glassand so forth, heated to 290° C. and baked for 5 minutes, a rhodium filmwas obtained. Furthermore, in this example, 2.39 moles of amino compoundwere used to 1 mole of metal.

Example 12

0.40 g (4.54 mmol) of N-methyl-1,3-diaminopropane, 0.10 g (0.77 mmol) of1,7-diaminoheptane (NH₂(CH₂)₇NH₂) and 0.10 g (1.12 mmol) of3-propoxypropylamine were added to 1.00 g (4.48 mmol) of gold cyanide(AuCN) and stirred. When 0.70 g (5.46 mmol) of cyclohexanoic acid(C₆H₁₁COOH) and 0.80 g (5.55 mmol) of 2-ethylhexanoic acid(CH₃CH₂CH(CH₃CH₂)COOH) were added and kneaded, a reddish-violettransparent paste was formed. When this was coated onto a substrate suchas glass and so forth and baked at 500-550° C., a gold mirror thin filmwas obtained. Furthermore, in this example, 1.44 moles of aminocompounds were used to 1 mole of metal.

Example 13

0.80 g (11.25 mmol) of lactonitrile, 0.60 g (5.87 mmol) of2,2-dimethyl-1,3-diaminopropane (NH₂CH₂C(CH₃)₂CH₂NH₂), 0.10 g (0.77mmol) of 1,7-diaminoheptane and 0.30 g (3.37 mmol) of3-methoxypropylamine were added to 1.00 g (4.48 mmol) of gold cyanideand stirred. A light orange, transparent paste was formed. When this wascoated onto a substrate such as glass and so forth and baked at 500-550°C., a gold film was obtained. When lactonitrile was added at this time,the organometallic compound became extremely stable, and was confirmedto remain in the form of a light orange, transparent paste withoutdemonstrating any decomposition whatsoever even after 4 years of storageat room temperature. Furthermore, in this example, 2.23 moles of aminocompounds were used to 1 mole of metal.

Example 14

0.70 g (4.42 mmol) of nonanoic acid (C₈H₁₇COOH) were added to 1.00 g(5.99 mmol) of silver acetate (CH₃COOAg) and kneaded. When 0.60 g (8.10mmol) of 1,3-diaminopropane were added to this and stirred, awhitish-gray paste was formed. This was further kneaded to form a brown,translucent paste. 0.04 g (0.37 mmol) of 1,4-phenylenediamine(C₆H₄(NH₂)₂) were added and kneaded until the paste became reddish-brownand translucent. 0.50 g (6.75 mmol) of propionic acid (CH₃CH₂COOH) wereadded and kneaded until a reddish-brown transparent paste was formed.When this was coated onto a substrate such as glass and so forth, heatedto 350° C. and baked for 5 minutes, a silver mirror silver film wasobtained. Furthermore, in this example, 1.41 moles of amino compoundswere used to 1 mole of metal.

Example 15

0.80 g (8.98 mmol) of 3-methoxypropylamine and 0.05 g (0.25 mmol) of1,12-diaminododecane (NH₂(CH₂)₁₂NH₂) were added to 1.00 g (5.99 mmol) ofsilver acetate and stirred. 1.00 g (7.68 mmol) of heptanoic acid(C₆H₁₃COOH) and 0.15 g (1.12 mmol) of malic acid (HOOCCH₂CH(OH)COOH)were then added and stirred. Moreover, when 0.60 g (8.10 mmol) of1,3-diaminopropane were added and kneaded until the color changed to apale brick color, a transparent paste formed. When this was coated ontoa substrate such as glass and so forth, heated to 300° C. and baked for10 minutes, a silver-colored film was obtained. Furthermore, in thisexample, 2.89 moles of amino compounds were used to 1 mole of metal.

Example 16

0.50 g (6.75 mmol) of 1,3-diaminopropane, 0.60 g (6.73 mmol) of3-methoxypropylamine and 0.05 g (0.24 mmol) of 1,12-diaminododecane wereadded to 1.00 g (5.99 mmol) of silver acetate and stirred. When 0.80 g(6.14 mmol) of heptanoic acid, 0.40 g (2.56 mmol) ofcyclohexanepropionic acid (C₆H₁₁(CH₂)₂C0OH), 0.15 g (1.12 mmol) of malicacid and 0.2 g (1.75 mmol) of 1,2-diaminocyclohexane were added andkneaded until the color changed to a dark reddish-orange color, atransparent paste was formed. When this was coated onto a substrate suchas glass and so forth, heated to 230° C. and baked for 10 minutes, asilver mirror film was obtained. Alternatively, when heated to 290° C.and baked for 10 minutes, a silver-colored film was obtained.Furthermore, in this example, 1.46 moles of amino compounds were used to1 mole of metal.

Example 17

0.50 g (6.75 mmol) of 1,3-diaminopropane and 0.40 g (2.53 mmol) ofnonanoic acid were added to 1.00 g (5.99 mmol) of silver acetate andkneaded to form a reddish-orange transparent paste. 0.10 g (0.88 mmol)of 1,2-diaminocyclohexane were added and kneaded. On the following day,a purple paste was formed. When this was coated onto a substrate such asglass and so forth, heated to 300° C. and baked for 5 minutes, a silvermirror film was obtained. Furthermore, in this example, 1.27 moles ofamino compounds were used to 1 mole of metal.

Example 18

0.80 g (7.01 mmol) of 1,2-diaminocyclohexane were added to 1.00 g (6.54mmol) of silver formate (HCOOAg) and kneaded. 0.50 g (6.58 mmol) ofethylene glycol monomethyl ether (CH₃OCH₂CH₂OH) were added to form ablackish-gray transparent paste. When this was coated onto a substratesuch as a film and so forth, heated to 130° C. and baked for 5 minutes,a slightly yellow-tinted silver film was obtained. Furthermore, in thisexample, 1.07 moles of amino compound were used to 1 mole of metal.

Example 19

0.80 g (10.80 mmol) of 1,3-diaminopropane were added to 1.00 g (6.54mmol) of silver formate and kneaded. When this was coated onto asubstrate such as a film and so forth, heated to 110° C. and baked for 5minutes, a silver film was obtained. When 0.60 g (9.98 mmol) of aceticacid (CH₃COOH) were added and kneaded, a stable paste was formed. Whenthis was coated onto a substrate such as a film and so forth, heated to120° C. and baked for 5 minutes, a gray silver film was obtained.Furthermore, in this example, 1.65 moles of amino compound were used to1 mole of metal.

Example 20

0.273 g (1.22 mmol) of palladium acetate powder were added to 0.80 g(4.79 mmol) of silver acetate crystals and mixed, after which 0.30 g(2.58 mmol) of 2-methyl-1,5-diaminopentane (NH₂(CH₂)₃CH(CH₃)CH₂NH₂),0.30 g (2.48 mmol) of 1-phenylethylamine (C₆H₅CH(NH₂)CH₃) and 0.30 g(3.44 mmol) of morpholine (0<(CH₂)₄>NH) were added and stirred. When0.30 g (2.30 mmol) of heptanoic acid were added and kneaded, a browntransparent paste was formed. When this was coated onto a substrate suchas glass and so forth, heated to 320° C. and baked for 10 minutes, amirrored silver-palladium alloy film was obtained. Furthermore, in thisexample, 1.41 moles of amino compounds were used to 1 mole of metal.

Example 21

1.20 g (10.51 mmol) of 1,2-diaminocyclohexane and 0.60 g (6.73 mmol) of3-methoxypropylamine were added to 1.00 g (2.59 mmol) of bismuth acetate(Bi(OOCCH₃)₂) and stirred. A light-coloredtransparent paste was formed.When this was coated onto a substrate such as glass and so forth, heatedto 250-350° C. and baked in a reducing atmosphere, a bismuth film wasobtained. Furthermore, in this example, 6.66 moles of amino compoundswere used to 1 mole of metal.

Example 22

1.10 g (9.63 mmol) of 1,2-diaminocyclohexane were added to 1.00 g (2.64mmol) of lead acetate trihydrate (Pb(OOCCH₃)₂,3H₂O) and stirred. 0.20 g(2.27 mmol) of isobutylic acid were further added and stirred. Alight-colored, nearly transparent paste was formed. When this was coatedonto a substrate such as glass and so forth, heated to 270-300° C. andbaked in a reducing atmosphere, a lead film was obtained. Furthermore,in this example, 3.65 moles of amino compound were used to 1 mole ofmetal.

Example 23

0.80 g (9.07 mmol) of N-methyl-1,3-diaminopropane were added to 1.00 g(4.01 mmol) of cobalt acetate tetrahydrate (Co(OOCCH₃)₂.4H₂O) andstirred. A dark purple, transparent paste was formed. When this wascoated onto a substrate such as glass and so forth, heated to 270-300°C. and baked in a reducing atmosphere, a cobalt film was obtained.Furthermore, in this example, 2.26 moles of amino compound were used to1 mole of metal.

Example 24

0.90 g (12.15 mmol) of 1,3-diaminopropane were added to 1.00 g (3.42mmol) of indium acetate (In(OOCCH₃)₃) and stirred. A slightly milkycolorless and transparent paste was formed. When this was coated onto asubstrate such as glass and so forth, heated to 220-230° C. and baked ina reducing atmosphere, an indium film was obtained. Furthermore, in thisexample, 3.55 moles of amino compound were used to 1 mole of metal.

Example 25

1.20 g (16.19 mmol) of 1,3-diaminopropane, 1.40 g (15.71 mmol) of3-methoxypropylamine and 1.20 g (6.90 mmol) of hydroxycitronellol(HOC(CH₃)₂CH₂CH₂CH₂CH(CH₃) CH₂CH₂OH) were added to 1.00 g (5.51 mmol) ofcopper acetate (Cu(OOCCH₃)₂) and stirred. A blue transparent liquid wasformed. When this was coated onto a substrate such as glass and soforth, heated to 350-360° C. and baked in a reducing atmosphere, acopper film was obtained. Furthermore, in this example, 5.79 moles ofamino compounds were used to 1 mole of metal.

Example 26

0.60 g (6.80 mmol) of N-methyl-1,3-diaminopropane and 0.60 g (6.73 mmol)of 3-methoxypropylamine were added to 1.00 g (3.35 mmol) of antimonyacetate (Sb(OOCCH₃)₃) and stirred. Moreover, when 0.40 g (3.92 mmol) ofpivalinic acid (CH₃C(CH₃)₂COOH) were added and kneaded, a milk-coloredtranslucent paste was formed. When this was coated onto a substrate suchas glass and so forth, heated to 360° C. and baked in a reducingatmosphere, an antimony film was obtained. Furthermore, in this example,4.04 moles of amino compounds were used to 1 mole of metal.

Example 27

When 1.10 g (14.65 mmol) of 2-amino-1-propanol (NH₂CH(CH₃)CH₂OH) wereadded to 1.00 g (3.75 mmol) of cadmium acetate dehydrate(Cd(OOCCH₃)₂.2H₂O) and stirred, a yellow transparent paste was formed.When this was treated at 200-240° C., coated onto a substrate such asglass and so forth, heated to 250° C. and baked in a reducingatmosphere, a cadmium film was obtained. Furthermore, in this example,3.91 moles of amino compound were used to 1 mole of metal.

Example 28

2.00 g (17.51 mmol) of 1,2-diaminocyclohexane were added to 1.00 g (1.76mmol) of ruthenium cyclohexanepropionate (Ru(OOCCH₂CH₂C₆H₁₁)₃) andstirred. When this paste was coated onto a substrate such as glass andso forth, heated to 300° C. and baked in a reducing atmosphere, aruthenium film was obtained. Furthermore, in this example, 9.95 moles ofamino compound were used to 1 mole of metal.

Example 29

When 2.00 g (17.51 mmol) of 1,2-diaminocyclohexane and 0.90 g (12.15mmol) of 1,3-diaminopropane were added to 1.00 g (4.84 mmol) of tinoxalate (Sn(COO)₂) and stirred, a cream-colored paste was formed. When1.00 g (6.40 mmol) of cyclohexanepropionic acid were added to this pasteand stirred, a translucent paste was formed. When this was coated onto asubstrate such as glass and so forth, heated to 360-400° C. and baked ina reducing atmosphere, a tin film was obtained. Furthermore, in thisexample, 6.13 moles of amino compounds were used to 1 mole of metal.

Example 30

0.273 g (1.22 mmol) of palladium acetate powder were added to 0.80 g(4.79 mmol) of silver acetate crystals and mixed, after which 0.30 g(2.58 mmol) of 2-methyl-1,5-diaminopentane, 0.30 g (2.48 mmol) of1-phenylethylamine and 0.30 g (3.44 mmol) of morpholine were added andstirred. Next, when 0.30 g (2.30 mmol) of heptanoic acid were added andkneaded, a brown, transparent paste was formed. When this was coatedonto a substrate such as glass and so forth, heated to 290° C. and bakedfor 15 minutes, a mirrored metal film was obtained. When this wassubjected to X-ray diffraction, there were no peaks observed at thelocation associated with silver alone or at the location associated withpalladium alone as is clear from (a) through (c) in FIG. 1. Instead, asingle peak appeared at a location intermediate to the locationsassociated with silver and palladium alone. Furthermore, FIG. 1(a) showsthe X-ray diffraction pattern, FIG. 1(b) shows the peak data of FIG.1(a), and FIG. 1(c) shows the peak data (card data) of silver andpalladium alone. As a result, a silverpalladium alloy having a meltingpoint of 290° C. considerably lower than the melting point of each metalwas confirmed to have been formed. Furthermore, in this example, 1.41moles of amino compounds were used to 1 mole of metal.

Example 31

When 0.70 g (7.94 mmol) of N-methyl-1,3-diaminopropane and 0.10 g (1.33mmol) of 1-amino-2-propanol (NH₂CH₂CH(CH₃)OH) were added to 1.00 g (4.02mmol) of nickel acetate tetrahydrate (Ni(OOCCH₃)₂.4H₂O) and stirred, ablue, transparent viscous liquid was formed. When 0.40 g of methylisobutyl ketone and 0.80 g of isobutylic acid were added to this liquidand stirred, a transparent paste was formed. When this was coated onto asubstrate such as glass and so forth, heated to 300° C. in a reducingatmosphere and baked, a nickel film was obtained. Furthermore, in thisexample, 2.31 moles of amino compounds were used to 1 mole of metal.

Example 32

When 1.30 g (14.74 mmol) of N-methyl-1,3-diaminopropane and 0.55 g (7.32mmol) of 1-amino-2-propanol were added to 1.00 g (2.34 mmol) ofmolybdenum acetate dimer crystals ([(CH₃COO)₂Mo]₂) and stirred, a brown,transparent liquid was formed. When 0.30 g of isoamyl methyl ketone and1.80 g of isobutylic acid were added to this liquid and stirred, atransparent paste was formed. When this was coated onto a substrate suchas glass and so forth, heated to 350° C. in a reducing atmosphere andbaked, a molybdenum film was obtained. Furthermore, in this example,4.72 moles of amino compounds were used to 1 mole of metal.

Example 33

When 0.70 g (7.94 mmol) of N-methyl-1,3-diaminopropane and 0.40 g (5.33mmol) of 1-amino-2-propanol were added to 1.00 g (4.31 mmol) ofmanganese acetate dehydrate (Mn(OOCCH₃)₂.2H₂O) and stirred, a darkbrown, transparent viscous liquid was formed. When 0.30 g of2,4-dimethyl-3-pentanone and 1.10 g of isobutylic acid were added tothis liquid and stirred, a transparent paste was formed. When this wascoated onto a substrate such as glass and so forth, heated to 370° C. ina reducing atmosphere and baked, a manganese film was obtained.Furthermore, in this example, 3.08 moles of amino compounds were used to1 mole of metal.

Example 34

When 0.50 g (5.67 mmol) of N-methyl-1,3-diaminopropane and 0.50 g (6.66mmol) of 1-amino-2-propanol were added to 1.00 g (4.56 mmol) of zincacetate dehydrate crystals (Zn(OOCCH₃)₂.2H₂O) and stirred, a colorless,transparent liquid was formed. When 0.30 g of ethylene glycol dimethylether and 1.00 g of 3-cyclohexanepropionic acid (C₆H₁₁CH₂CH₂COOH) wereadded to this liquid and stirred, a transparent paste was formed. Whenthis was coated onto a substrate such as glass and so forth, heated to300° C. in a reducing atmosphere and baked, a zinc film was obtained.Furthermore, in this example, 2.70 moles of amino compounds were used to1 mole of metal.

Example 35

When 0.85 g (9.64 mmol) of N-methyl-1,3-diaminopropane and 0.50 g (6.66mmol) of 1-amino-2-propanol were added to 1.00 g (1.66 mmol) of chromiumacetate ((CH₃COO)₇Cr₃(OH)₂) and stirred, a green transparent liquid wasformed. A purple color was visible when this was looked through anincandescent lamp, and a blackish-gray color was visible when this waslooked through a fluorescent lamp. When 0.30 g of 2-heptanone and 1.30 gof isobutylic acid were added and stirred, a transparent paste wasformed. When this was coated onto a substrate such as glass and soforth, heated to 340° C. in a reducing atmosphere and baked, apowder-like chromium film was obtained. Furthermore, in this example,3.27 moles of amino compounds were used to 1 mole of metal.

Example 36

When 0.60 g (6.80 mmol) of N-methyl-1,3-diaminopropane and 0.50 g (6.66mmol) of 1-amino-2-propanol were added to 1.00 g (5.75 mmol) of ironacetic anhydride (Fe(OOCCH₃)₂) and stirred, a brown, transparent viscousliquid was formed. When 0.30 g of diethylene glycol dimethyl ether and1.10 g of isobutylic acid were added to this liquid and stirred, atransparent paste was formed. When this was coated onto a substrate suchas glass and so forth, heated to 350° C. in a reducing atmosphere andbaked, an iron film was obtained. Furthermore, in this example, 2.34moles of amino compounds were used to 1 mole of metal.

The metal paste of the present invention is characterized by blending amedium in the form of an amino compound into an organo- orinorganometallic compound of a metal that is a solid at ordinarytemperature and belongs to groups 3 through 15 of the periodic table toform a paste that demonstrates coatable viscosity.

Thus, an organo- or inorganometallic compound can be directly and easilyformed into a paste by a simple procedure comprising of adding ageneral-purpose, inexpensive amino compound to a general-purpose,inexpensive solid organo- or inorganometallic compound and stirring, andwithout requiring the use of special compounds or synthesis methods.Moreover, the metal paste of the present invention can be baked at lowtemperatures (within the range of, for example, 90-550° C.) to obtainvarious types of metal films. Consequently, metal films of various typesof metals or alloys can be manufactured continuously and inexpensivelywith an industrially simple process and apparatus even on various typesof generalpurpose, inexpensive substrates having a low softening point.

In addition, since baking can be carried out at low temperatures, thesurface of the metal is less susceptible to oxidation than in the caseof baking at high temperatures, thereby allowing the obtaining of ametal film with high electrical conductivity.

As Namely, since baking can be carried out at low temperatures using aninexpensive organo- or inorganometallic compound, in addition to beingable to hold equipment costs of metal film production to a low level, ametal film can be formed on a general-purpose, inexpensive substratehaving a low melting point. For example, although silver-palladium metalfilm is currently formed at a high temperature of 950° C., in thepresent invention, a homogenous silver-palladium film can be formed on aglass substrate by baking at approximately 320° C.

What is claimed is:
 1. A metal paste being capable of forming a uniformand electrically conductive metal film by low-temperature bakingcomprising a nitrate salt, cyano compound, carbonyl compound or organicacid salt of a metal that is a solid at ordinary temperature and belongsto group 3 through 15 of the periodic table, and a primary or secondaryamino compound as medium, which can make the former change into a liquidor mud to allow the obtaining of a coatable, viscous and homogenousmetal paste.
 2. The paste according to claim 1, wherein said metalbelonging to groups 3 through 15 of the periodic table is Pd, Pt, Rh,Au, Ag, Co, Pb, Cu, In, Sn, Sb, Ru, Cd, Ti, Bi, Cr, Mn, Fe, Ni, Zn orMo.
 3. The paste according to claim 1, wherein said amino compound is analiphatic or aromatic amine.
 4. The paste according to claim 3, whereinsaid aliphatic or aromatic amine is 1,3-diaminopropane,N-methyl-1,3-diaminopropane, 2,2-dimethyl-1,3-diaminopropane,1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane,1,7-diaminoheptane, 1,12-diaminododecane, 2-methyl-1,5-diaminopentane,2-methoxyethylamine, 3-methoxypropylamine, 3-propoxypropylamine,2-amino-1-propanol, N-methylaniline, 1-phenylethylamine,1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine ormorpholine.
 5. The paste according to claim 1, additionally containingan aliphatic or aromatic mono- or dicarboxylic acid or its ester.
 6. Thepaste according to claim 5, wherein said aliphatic or aromatic mono- ordicarboxylic acid or its ester is formic acid, oxalic acid, acetic acid,propionic acid, butylic acid, 2-ethylhexanoic acid, heptanoic acid,nonanoic acid, malic acid, pivalinic acid, cyclohexanoic acid,cyclohexanepropionic acid, hydroxybenzoic acid, phenylacetic acid,methylbenzoate, ethylhydroxybenzoate, ethyl2-ethylhexanoate, ethylacetate, ethyl hydroxyacetate or methyl linolate.
 7. The paste accordingto claim 1, additionally containing an aliphatic or aromatic mono- orpolyhydric alcohol.
 8. The paste according to claim 7, wherein saidaliphatic or aromatic mono- or polyhydric alcohol is nerol, citronellol,hydroxynerol, hydroxycitronellol, ethyl alcohol, propyl alcohol, butylalcohol, hexyl alcohol, ethylhexyl alcohol, decyl alcohol, benzylalcohol, hydroxybenzyl alcohol, phenylethyl alcohol, phenylpropylalcohol, dihydroxybenzene, cyclohexyl alcohol, ethylcyclohexyl alcohol,butylcyclohexyl alcohol, methoxybenzyl alcohol, piperonyl alcohol,ethylene glycol, propylene glycol,1,2-butanediol,2,2-dimethyl-1,3-propanediol, ethylene glycol monomethylether, diethylene glycol monoethyl ether, triethylene glycol monopropylether, propylene glycol monomethyl ether, propylene glycol monoethylether, tripropylene glycol monopropyl ether, diethylene glycol,dipropylene glycol, ethylene glycol monobutyl ether and1-butoxy-2-propanol, lactonitrile, hydroxyacetonitrile, ethylenecyanohydrin or acetone cyanohydrin.
 9. The paste according to claim 1,additionally containing an aliphatic or aromatic ketone.
 10. The pasteaccording to claim 9, wherein said aliphatic or aromatic ketone isacetone, ethyl methyl ketone, 2-pentanone, 3-pentanone,3-methyl-2-butanone, 2-hexanone, 3-hexanone, methyl butyl ketone,3-methyl-2-pentanone, 2-heptanone, 3-heptanone, 4-heptanone, amyl methylketone, ethyl butyl ketone, 2,4-dimethyl-3-pentanone, 2-octanone,3-octanone, 4-octanone, 2,5-dimethyl-3-hexanone, cyclohexanone,methylcyclohexanone, acetophenone, acetylacetone, 2,3-butanedione,2,3-pentanedione, 3,4-hexanedione, 2,5-hexanedione or cyclohexanedione.11. The paste according to claim 1, additionally containing an aliphaticor aromatic ether.
 12. The paste according to claim 11, wherein saidaliphatic or aromatic ether is ethylene glycol dimethyl ether, ethyleneglycol diethyl ether, ethylene glycol dipropyl ether, propylene glycoldimethyl ether, propylene glycol diethyl ether, diethylene glycoldimethyl ether, diethylene glycol diethyl ether, dipropylene glycoldimethyl ether, dipropylene glycol diethyl ether, propylene glycoldipropyl ether, 4-methoxy-2-butanone, 4-ethoxy-2-butanone,4-methoxy-2-butanone, 2-methoxy-2-methyl-4-pentanone, acetal, acetonediethylacetal,2,2-dimethoxypropane, anisole or dimethoxybenzene.
 13. Thepaste according to claim 1, that is used in the fields of electronicmaterials, mechanical materials, optical materials, sanitary materials,domestic materials, agricultural materials and pharmaceutical materials.14. A production process of a metal film comprising forming a metal filmby coating a metal paste according to claim 1 onto a substrate andbaking at 90-550° C.
 15. The production process according to claim 14,wherein said substrate is a substrate for an electrically conductivematerial, resistor material, heat transmitting material, heat insulatingmaterial, light and electromagnetic wave reflecting and absorbingmaterials, corrosion-resistant material, mechanically strong material,material for absorbing abrasion, material for catarysis, metal lustermaterial, material for coloring, material for decoration or microbialgrowth-inhibiting material, which is made of ceramics, metal, glass,plastic or paper.